qemu/0012-scsi-pvscsi-check-comm...

101 lines
3.3 KiB
Diff

From: Prasad J Pandit <pjp@fedoraproject.org>
Date: Mon, 23 May 2016 16:18:05 +0530
Subject: [PATCH] scsi: pvscsi: check command descriptor ring buffer size
(CVE-2016-4952)
Vmware Paravirtual SCSI emulation uses command descriptors to
process SCSI commands. These descriptors come with their ring
buffers. A guest could set the ring buffer size to an arbitrary
value leading to OOB access issue. Add check to avoid it.
Reported-by: Li Qiang <liqiang6-s@360.cn>
Signed-off-by: Prasad J Pandit <pjp@fedoraproject.org>
Cc: qemu-stable@nongnu.org
Message-Id: <1464000485-27041-1-git-send-email-ppandit@redhat.com>
Reviewed-by: Shmulik Ladkani <shmulik.ladkani@ravellosystems.com>
Reviewed-by: Dmitry Fleytman <dmitry@daynix.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
(cherry picked from commit 3e831b40e015ba34dfb55ff11f767001839425ff)
---
hw/scsi/vmw_pvscsi.c | 24 ++++++++++++++++++++----
1 file changed, 20 insertions(+), 4 deletions(-)
diff --git a/hw/scsi/vmw_pvscsi.c b/hw/scsi/vmw_pvscsi.c
index e690b4e..e1d6d06 100644
--- a/hw/scsi/vmw_pvscsi.c
+++ b/hw/scsi/vmw_pvscsi.c
@@ -153,7 +153,7 @@ pvscsi_log2(uint32_t input)
return log;
}
-static void
+static int
pvscsi_ring_init_data(PVSCSIRingInfo *m, PVSCSICmdDescSetupRings *ri)
{
int i;
@@ -161,6 +161,10 @@ pvscsi_ring_init_data(PVSCSIRingInfo *m, PVSCSICmdDescSetupRings *ri)
uint32_t req_ring_size, cmp_ring_size;
m->rs_pa = ri->ringsStatePPN << VMW_PAGE_SHIFT;
+ if ((ri->reqRingNumPages > PVSCSI_SETUP_RINGS_MAX_NUM_PAGES)
+ || (ri->cmpRingNumPages > PVSCSI_SETUP_RINGS_MAX_NUM_PAGES)) {
+ return -1;
+ }
req_ring_size = ri->reqRingNumPages * PVSCSI_MAX_NUM_REQ_ENTRIES_PER_PAGE;
cmp_ring_size = ri->cmpRingNumPages * PVSCSI_MAX_NUM_CMP_ENTRIES_PER_PAGE;
txr_len_log2 = pvscsi_log2(req_ring_size - 1);
@@ -192,15 +196,20 @@ pvscsi_ring_init_data(PVSCSIRingInfo *m, PVSCSICmdDescSetupRings *ri)
/* Flush ring state page changes */
smp_wmb();
+
+ return 0;
}
-static void
+static int
pvscsi_ring_init_msg(PVSCSIRingInfo *m, PVSCSICmdDescSetupMsgRing *ri)
{
int i;
uint32_t len_log2;
uint32_t ring_size;
+ if (ri->numPages > PVSCSI_SETUP_MSG_RING_MAX_NUM_PAGES) {
+ return -1;
+ }
ring_size = ri->numPages * PVSCSI_MAX_NUM_MSG_ENTRIES_PER_PAGE;
len_log2 = pvscsi_log2(ring_size - 1);
@@ -220,6 +229,8 @@ pvscsi_ring_init_msg(PVSCSIRingInfo *m, PVSCSICmdDescSetupMsgRing *ri)
/* Flush ring state page changes */
smp_wmb();
+
+ return 0;
}
static void
@@ -770,7 +781,10 @@ pvscsi_on_cmd_setup_rings(PVSCSIState *s)
trace_pvscsi_on_cmd_arrived("PVSCSI_CMD_SETUP_RINGS");
pvscsi_dbg_dump_tx_rings_config(rc);
- pvscsi_ring_init_data(&s->rings, rc);
+ if (pvscsi_ring_init_data(&s->rings, rc) < 0) {
+ return PVSCSI_COMMAND_PROCESSING_FAILED;
+ }
+
s->rings_info_valid = TRUE;
return PVSCSI_COMMAND_PROCESSING_SUCCEEDED;
}
@@ -850,7 +864,9 @@ pvscsi_on_cmd_setup_msg_ring(PVSCSIState *s)
}
if (s->rings_info_valid) {
- pvscsi_ring_init_msg(&s->rings, rc);
+ if (pvscsi_ring_init_msg(&s->rings, rc) < 0) {
+ return PVSCSI_COMMAND_PROCESSING_FAILED;
+ }
s->msg_ring_info_valid = TRUE;
}
return sizeof(PVSCSICmdDescSetupMsgRing) / sizeof(uint32_t);